I'm running a Merlin head using papywizard on a Raspberry Pi, connected with a USB to serial connector. Everything is going great, except for one issue. I cannot get the camera to trigger at regular intervals for the time lapse.

For example, with the camera set to shooting at 1/10 of a sec, and Merlin set with a stablisation delay of 1s and time value of 1 sec, I get photos at strange intervals, some times 2 seconds apart, sometimes 4 seconds. I cant see a pattern to the strange invervals.

This also happens with the camera set to longer exposure times. eg 8sec exposure, with Merlin stabalisation delay 1sec and time value of 8sec. I get anything from 9 seconds to 14 seconds between shots.

I guess there is probably a post that describes why, but I could not find it. Can someone point me in the right direction?

Thanks,Simon

PS Despite this shooting in iceland is going great! I'll put up some examples when I can get a chance

Thanks for the quick response guys, you are both making papywizard a really fantastic community to be part of!

Ok details.

I did a test moving the Merlin head from 0.0 to 0.5 degrees by 0.1degree steps in yaw between each shot, using a preset file I built myself. The camera is fully manual, 1/10s exposure, manual focus. Papywizard settings have 0.5s stabalisation and 1s time value.

When I run the script I cannot see the head move, but that is only due to the small step size, I can see the change when I run more steps.

The camera triggers, but the interval between shots is very strange. In the test setup I got 6 shots with interval: 2s, 4s, 2s, 4s and 4s.

sbell wrote:Could this have something to do with the pulse width high, and pulse width low settings for the camera trigger in the Merlin head plugin? I don't really understand what these parameters do.

Thanks for the tip, Chronomotion looks like an interesting option. Do you have any experience using it? I have installed and got it talking to the Merlin, but can't figure out much more than that! The information on how to use it is much more limited, no real info in the wiki and can't find much in the forums.

I'll also try on the timescapes forum as Sebastian seems to spend some time there

Creating a demo video showing how the software can be used and what it is capable of is the next thing I want to work on.So far you are right there is not a lot of usage documentation.

Since I come from the video compositing/editing and 3D animation world my approach was to center the software around a timeline with keyframes.So you set up your movement curves for both pan and tilt, create bezier keyframes and when you are happy you "play back" the entire timeline with the head.

Some notes:-) double click into the timeline to create a new keyframe-) the animation will run until it reaches the last keyframe in one of the channels - so you need to make sure both channels have the last keyframe at the desired end of your shot-) triggering the cameras shutter is done via the head itself so you need to connect head and camera with a shutter cable

Let me know if you need more help.Maybe we can work together on creating the documentation on the apertus wiki?

Thanks for the information. I just got back from a 2 week long holiday in Iceland with a good mate, aiming to shoot the Northern lights in time lapse. We're very happy with our results and videos will follow after they've been through editing!

From our experience on the trip we have decided that a fully software control option is just not optimum. Although it is the solution with the most flexibility, software requires a computer to run the setup. We used a Raspberry Pi which was great for power saving, but it added complexity in terms of the number of connections and number of different voltages we needed to run the system.

We have decided to look into fully hardware options, eg MX2. If this does not give all the options we want then I am excited about building my own controller based on an Arduino or similar product. I will do some research on what the MX2 does and decide if it suits us. If not then I will start an alternative project based on the idea and ideals of open source hardware. That will mean a lot of questions in the forums about what people want from a hardware based time lapse controller!

Thanks for the information. I just got back from a 2 week long holiday in Iceland with a good mate, aiming to shoot the Northern lights in time lapse. We're very happy with our results and videos will follow after they've been through editing!

From our experience on the trip we have decided that a fully software control option is just not optimum. Although it is the solution with the most flexibility, software requires a computer to run the setup. We used a Raspberry Pi which was great for power saving, but it added complexity in terms of the number of connections and number of different voltages we needed to run the system.

We have decided to look into fully hardware options, eg MX2. If this does not give all the options we want then I am excited about building my own controller based on an Arduino or similar product. I will do some research on what the MX2 does and decide if it suits us. If not then I will start an alternative project based on the idea and ideals of open source hardware. That will mean a lot of questions in the forums about what people want from a hardware based time lapse controller!

I think you are the first Chronomotion real life environment production tester? How has it been?Do you think the complexity can be reduced by creating a more sophisticated device based on the raspberry pi?

Dynamic Perceptions new MoCoBus based system will deliver what you are after.

I am sorry to admit that I did not end up using Chronomotion. We stuck with papywizard and just dealt with the fact that the timing interval was not always the same.

This decision was mainly because I could not figure out how to correctly use the motion time line that presets the motion of the Merlin. We also decided that as we want a hardware solution in the future that it would not be worth investing the time to learn a new piece of software.

I am very keen to find some thing (self made or otherwise) that can reduce the complexity of things in the field. We spent the cloudy nights (we had more than a few!) brainstorming the best way to do this with hardware and think we have a good idea of what we would like. I think it would be best based on an arduino rather than a Raspberry Pi.

If you're keen to hear more about our ideas I can send you the write up we made of it.